RCote Posted October 25, 2016 Share Posted October 25, 2016 1999 R1100RT with 98000 miles. Stalls at idle, rpm fluctuates 500 rpm, sputters and bucks under way. I've had it to the dealer and to reputable BMW bike mechanic. Still unable to resolve issue. Was told that there are several of these in this model that are doing this but with no fix as of yet. Any help would be greatly appreciated. Here's whats been done so far. 1. valves adjusted 2. plugs replaced 3. hall effect sensor replaced 4. ignition modual replaced 5. swapped computer with a known good one, did not follow problem 6. replaced fuel filter and checked fuel pressure 7. throttle bodies synced 8. check throttle bodies for ware and functionality I was told it could be a ground issue and that to chase it down and do any further diagnostics may be more than the bike is worth at this point. Thoughts? Thanks Rick Link to comment
Jim Moore Posted October 25, 2016 Share Posted October 25, 2016 You've done all the things I would do. Sounds like a fuel delivery problem. Check to see that all your fuses and relays are completely seated. after that I'd replace the u-shaped internal fuel line. After that I'd do a compression check. Link to comment
dirtrider Posted October 25, 2016 Share Posted October 25, 2016 1999 R1100RT with 98000 miles. Stalls at idle, rpm fluctuates 500 rpm, sputters and bucks under way. I've had it to the dealer and to reputable BMW bike mechanic. Still unable to resolve issue. Was told that there are several of these in this model that are doing this but with no fix as of yet. Any help would be greatly appreciated. Here's whats been done so far. 1. valves adjusted 2. plugs replaced 3. hall effect sensor replaced 4. ignition modual replaced 5. swapped computer with a known good one, did not follow problem 6. replaced fuel filter and checked fuel pressure 7. throttle bodies synced 8. check throttle bodies for ware and functionality I was told it could be a ground issue and that to chase it down and do any further diagnostics may be more than the bike is worth at this point. Morning Rick Does you bike still have the original CCP in the fuse box? (if so try removing it then do a test ride) If no CCP in the fuse box (or incorrect CCP) then try removing it & take a test ride. (if CCP in or out makes a difference then also look at the o2 sensor) Have you measured the resistance in the igniting coil & both spark plug wires? (also make darn sure that both side spark plug wires are FULLY plugged into the coil) Also look for o2 sensor wire to be running along or too close to R/H spark plug wire. Make sure that R/H TB cam isn't contacting the R/H spark plug wire at idle (I have seem some actually cut into wire) Have you run a cold cranking compression test ? If not then you might do that--(be sure to remove fuse #5 & hold throttle wide open for compression test) How worn are you TB throttle shafts & shaft bushings????? -- a decent air leak there can drive idle crazy) Is your TPS (Throttle Position Sensor) set correctly & tracks smoothly on the low output side? Much more but this should get you started-- Link to comment
McDuugle Posted October 25, 2016 Share Posted October 25, 2016 If it were me I would also clean the injectors, just to make sure there is no inconsistencies in fuel delivery. I will probably do that on mine soon. After that you may have to re-sync the throttle bodies. Link to comment
Michaelr11 Posted October 26, 2016 Share Posted October 26, 2016 Rick - I'll echo what DR and McDuggle offered up in their responses. Check or rebuild the throttle body shafts and bushes, check TPS voltage setting and clean the fuel injectors. Make sure you resync the throttle bodies after that and set the idle at around 1050 or 1100 rpm. Also where are you located so a nearby member might be able to assist you? Link to comment
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